Diterpenoids are a class of compounds found in wood extractives of many tree species and can be generally grouped into two subclasses comprising abietanes and pimeranes. Abietane-type acids have an isopropyl chain at the C-13 position while primerane-type acids have methyl and vinyl substituents at this position. Wood extractives comprising abietane and primerane acids can comprise natural rosins.
Several different types of natural rosins exist, including wood rosins, gum rosins, and tall oil rosins. Wood, gum, and tall oil rosins, however, are produced by various processes. Wood rosins, for example, are produced via a multistage purification and refining process involving solvent extraction of pine wood chips followed by solvent-solvent refining of the crude rosin extract. Gum rosins, nevertheless, are generally produced by a single stage flash distillation process wherein the terpene (turpentine) fraction is volatilized leaving the rosin as a bottoms product. Tall oil rosins are the by-products of the fractionation of tall oil.
Although produced by varying processes, these natural rosins have similar components. Wood rosins and gum rosins, for example, comprise similar abietane and pimarane contents. Gas chromatographic analysis reveals that wood and gum rosins comprise various percentages of diterpenoid acids, such as pimaric acid, isopimaric acid, palustric acid, abietic acid, dehydroabietic acid, and neoabietic acid, in addition to other contents.
Natural rosins comprising wood rosins, gum rosins, and tall oil rosins are useful in a variety of applications. Natural rosins, for example, are used in binders for inks, tackifying resins, and pressure sensitive adhesives.
In some circumstances, natural rosins can be modified to demonstrate various physical and chemical properties. Modification of natural rosins can be accomplished through chemical modification of rosin components. Diterpenoid acid components of wood and gum rosins as delineated above, for example, can be chemically modified to produce chemically modified rosins. As used herein, a chemically modified rosin is defined as a rosin in which one or more components of the rosin has been chemically reacted. Chemically modified rosins are useful in a number of applications including paper production processes and sizings for natural and synthetic fibers. One area in which chemically modified rosins and natural rosins find application is in the treatment of glass fibers.
Various chemical treatments exist for glass-type surfaces such as glass fibers to facilitate their processability as well as their interaction with other substances or media. In glass fiber applications, a coating composition or sizing composition is applied to at least a portion of individual glass filaments to protect the filaments from abrasion and to assist in processing of the filaments. As used herein, the terms “sizing composition,” “sizing,” “binder composition,” “binder,” or “size” refer to a coating composition applied to glass filaments or glass fibers. Sizing compositions may provide protection through subsequent processing steps, such as those where the fibers pass by contact points in the winding of the fibers and strands onto a forming package, drying the aqueous-based or solvent based sizing composition to remove the water or solvent, twisting from one package to a bobbin, chopping in a wet or dry condition, roving into larger bundles or groups of strands, unwinding for use as a reinforcement, and other downstream processes.
In addition, sizing compositions can play a dual role when placed on fibers that reinforce polymeric matrices in the production of fiber-reinforced plastics. In such applications, the sizing composition provides protection and also can provide compatibility between the fiber and the matrix polymer or resin. Glass fibers, for example, in the forms of woven and nonwoven fabrics and mats and rovings have been used with various matrices, such as thermosetting and thermoplastic resins, as reinforcing components. In such applications, it can be desirable to produce favorable interfacial interactions between the glass fiber and the polymer matrix while also facilitating processing and manufacturing considerations.
Sizing compositions can contain a variety of chemical species wherein each of the individual chemical species performs one or more functions. A sizing composition, for example, may comprise film forming agents that facilitate spreading of the sizing composition across the glass surface to ensure homogenous coating. Sizing compositions can also comprise coupling agents which promote favorable interaction of a glass surface with various matrices. In addition to film forming and coupling agents, sizing compositions can comprise various ionic or non-ionic lubricants, biocides, antistatic agents, antifoaming agents, and/or wetting agents.
Diterpenoid compounds and natural and chemically modified rosins comprising such compounds can provide a number of desirable characteristics when coated on a glass fiber. Disadvantages under some circumstances currently exist, however, with some diterpenoid compounds and related rosins comprising these compounds. Diterpenoid derivatives and related rosins, for example, can be expensive and difficult to manufacture.
It would be desirable to provide other terpenoid compounds and derivatives and rosins comprising such compounds and derivatives. It would additionally be desirable to provide sizing compositions comprising such terpenoid compounds and derivatives.